So long as the game was linked to a google+ account originally, you can use any android device or emulator to:
1. Install Boom Beach and go through the tutorial part of the game. It is important to go through the "mandatory" part at the beginning of the game.
2. Shutdown the game
3. Add your Google+ account to the android device.
4. Start BB and click "sign in"
You should see a list of Google+ accounts that are installed on the android device. Just pick yours and you should have your hard earned base back.
At this point you can go through the android->IOS transfer process. Once that is done, you may want to remove your Google+ account from the borrowed android device.
Good Luck